The Portland-based electric utility filed its 2020 integrated resource plan with state regulators, a document highly-anticipated by watchdog groups and environmentalists to see what the company would do with the Boardman plant.
The 374-megawatt plant, while a reliable source of low-cost power, is also a heavy polluter.
The state Department of Environmental Quality in June endorsed a plan to retrofit Boardman with upgraded technology that would reduce its emissions by 80 percent.
But the plan is also estimated to cost PGE as much as $600 million, while pushing electricity rates up between 3 percent and 4 percent by 2018.
While PGE could have chosen to close down the Boardman plant, it is instead electing to install the retrofits, retaining the lower-cost baseload power at least through 2040.
It will meet new demand with as much as 500 megawatts of baseload capacity from a new natural gas plant to be in service by 2015 a comparatively cleaner fuel source, but one that is often at risk of volatile price fluctuations.
PGE anticipates that its customers demand for electricity will increase by an average of 2.3 percent per year, or 20 percent by 2020.
In addition to Boardman and the new natural gas plants, it is calling for adding another 122 mw of renewable energy on top of the 550 mw it will have in its portfolio by the end of 2010. It will also seek an increased emphasis on energy efficiency measures, and plans on installing a 500-kilovolt transmission line connecting the southern portion of the utility's service territory near Salem with the Boardman and Coyote Springs plants near Boardman.
PGE, which has been working on the draft plan for 18 months, is seeking public input on the resource proposal.